Commit 45cd5290 authored by Russell King's avatar Russell King
Browse files

ARM: add dma coherent region reporting via procfs 



Add a new seqfile for reporting coherent DMA allocations.  This contains
the address range, size and the function which was used to allocate
each region, allowing these allocations to be viewed in much the same
way as /proc/vmallocinfo.

The DMA coherent region has limited space, so this allows allocation
failures to be viewed, as well as finding out how much space is being
used.

Make sure this file is only readable by root - same as vmallocinfo - to
prevent information leakage.

Acked-by: default avatarNicolas Pitre <nico@linaro.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 6bebb572

arch/arm/mm/dma-mapping.c

+13 −7
Original line number Diff line number Diff line
@@ -214,7 +214,8 @@ static int __init consistent_init(void) 
core_initcall(consistent_init);



static void *

__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot)

__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,

	const void *caller)

{

	struct arm_vmregion *c;

	size_t align;
@@ -241,7 +242,7 @@ __dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot) 
	 * Allocate a virtual address in the consistent mapping region.

	 */

	c = arm_vmregion_alloc(&consistent_head, align, size,

			    gfp & ~(__GFP_DMA | __GFP_HIGHMEM));

			    gfp & ~(__GFP_DMA | __GFP_HIGHMEM), caller);

	if (c) {

		pte_t *pte;

		int idx = CONSISTENT_PTE_INDEX(c->vm_start);
@@ -320,14 +321,14 @@ static void __dma_free_remap(void *cpu_addr, size_t size) 


#else	/* !CONFIG_MMU */



#define __dma_alloc_remap(page, size, gfp, prot)	page_address(page)

#define __dma_alloc_remap(page, size, gfp, prot, c)	page_address(page)

#define __dma_free_remap(addr, size)			do { } while (0)



#endif	/* CONFIG_MMU */



static void *

__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,

	    pgprot_t prot)

	    pgprot_t prot, const void *caller)

{

	struct page *page;

	void *addr;
@@ -349,7 +350,7 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, 
		return NULL;



	if (!arch_is_coherent())

		addr = __dma_alloc_remap(page, size, gfp, prot);

		addr = __dma_alloc_remap(page, size, gfp, prot, caller);

	else

		addr = page_address(page);
@@ -374,7 +375,8 @@ dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gf 
		return memory;



	return __dma_alloc(dev, size, handle, gfp,

			   pgprot_dmacoherent(pgprot_kernel));

			   pgprot_dmacoherent(pgprot_kernel),

			   __builtin_return_address(0));

}

EXPORT_SYMBOL(dma_alloc_coherent);
@@ -386,7 +388,8 @@ void * 
dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)

{

	return __dma_alloc(dev, size, handle, gfp,

			   pgprot_writecombine(pgprot_kernel));

			   pgprot_writecombine(pgprot_kernel),

			   __builtin_return_address(0));

}

EXPORT_SYMBOL(dma_alloc_writecombine);
@@ -723,6 +726,9 @@ EXPORT_SYMBOL(dma_set_mask); 


static int __init dma_debug_do_init(void)

{

#ifdef CONFIG_MMU

	arm_vmregion_create_proc("dma-mappings", &consistent_head);

#endif

	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);

	return 0;

}

arch/arm/mm/vmregion.c

+75 −1
Original line number Diff line number Diff line 
#include <linux/fs.h>

#include <linux/spinlock.h>

#include <linux/list.h>

#include <linux/proc_fs.h>

#include <linux/seq_file.h>

#include <linux/slab.h>



#include "vmregion.h"
@@ -36,7 +39,7 @@ 


struct arm_vmregion *

arm_vmregion_alloc(struct arm_vmregion_head *head, size_t align,

		   size_t size, gfp_t gfp)

		   size_t size, gfp_t gfp, const void *caller)

{

	unsigned long start = head->vm_start, addr = head->vm_end;

	unsigned long flags;
@@ -52,6 +55,8 @@ arm_vmregion_alloc(struct arm_vmregion_head *head, size_t align, 
	if (!new)

		goto out;



	new->caller = caller;



	spin_lock_irqsave(&head->vm_lock, flags);



	addr = rounddown(addr - size, align);
@@ -129,3 +134,72 @@ void arm_vmregion_free(struct arm_vmregion_head *head, struct arm_vmregion *c) 


	kfree(c);

}



#ifdef CONFIG_PROC_FS

static int arm_vmregion_show(struct seq_file *m, void *p)

{

	struct arm_vmregion *c = list_entry(p, struct arm_vmregion, vm_list);



	seq_printf(m, "0x%08lx-0x%08lx %7lu", c->vm_start, c->vm_end,

		c->vm_end - c->vm_start);

	if (c->caller)

		seq_printf(m, " %pS", (void *)c->caller);

	seq_putc(m, '\n');

	return 0;

}



static void *arm_vmregion_start(struct seq_file *m, loff_t *pos)

{

	struct arm_vmregion_head *h = m->private;

	spin_lock_irq(&h->vm_lock);

	return seq_list_start(&h->vm_list, *pos);

}



static void *arm_vmregion_next(struct seq_file *m, void *p, loff_t *pos)

{

	struct arm_vmregion_head *h = m->private;

	return seq_list_next(p, &h->vm_list, pos);

}



static void arm_vmregion_stop(struct seq_file *m, void *p)

{

	struct arm_vmregion_head *h = m->private;

	spin_unlock_irq(&h->vm_lock);

}



static const struct seq_operations arm_vmregion_ops = {

	.start	= arm_vmregion_start,

	.stop	= arm_vmregion_stop,

	.next	= arm_vmregion_next,

	.show	= arm_vmregion_show,

};



static int arm_vmregion_open(struct inode *inode, struct file *file)

{

	struct arm_vmregion_head *h = PDE(inode)->data;

	int ret = seq_open(file, &arm_vmregion_ops);

	if (!ret) {

		struct seq_file *m = file->private_data;

		m->private = h;

	}

	return ret;

}



static const struct file_operations arm_vmregion_fops = {

	.open	= arm_vmregion_open,

	.read	= seq_read,

	.llseek	= seq_lseek,

	.release = seq_release,

};



int arm_vmregion_create_proc(const char *path, struct arm_vmregion_head *h)

{

	proc_create_data(path, S_IRUSR, NULL, &arm_vmregion_fops, h);

	return 0;

}

#else

int arm_vmregion_create_proc(const char *path, struct arm_vmregion_head *h)

{

	return 0;

}

#endif

arch/arm/mm/vmregion.h

+4 −1
Original line number Diff line number Diff line
@@ -19,11 +19,14 @@ struct arm_vmregion { 
	unsigned long		vm_end;

	struct page		*vm_pages;

	int			vm_active;

	const void		*caller;

};



struct arm_vmregion *arm_vmregion_alloc(struct arm_vmregion_head *, size_t, size_t, gfp_t);

struct arm_vmregion *arm_vmregion_alloc(struct arm_vmregion_head *, size_t, size_t, gfp_t, const void *);

struct arm_vmregion *arm_vmregion_find(struct arm_vmregion_head *, unsigned long);

struct arm_vmregion *arm_vmregion_find_remove(struct arm_vmregion_head *, unsigned long);

void arm_vmregion_free(struct arm_vmregion_head *, struct arm_vmregion *);



int arm_vmregion_create_proc(const char *, struct arm_vmregion_head *);



#endif

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